Using a nondegenerate four-wave mixing process based on a double-Λ scheme in hot cesium vapor, we generate quantum correlated twin beams with a maximum intensity-difference squeezing of 6.5 dB. The substantially improved squeezing can be mainly attributed to very good frequency and phase-difference stability between the pump and probe beams in our experiment. Intensity-difference squeezing can be observed within a wide experimental parameter range, which guarantees its robust generation. Since this scheme produces multi-spatial-mode twin beams at the Cs D1 line, it is of interest for experiments involving quantum imaging and coherent interfaces between atomic and solid-state systems.
@article{arxiv.1710.06706,
title = {Generating quantum correlated twin beams by four-wave mixing in hot cesium vapor},
author = {Rong Ma and Wei Liu and Zhongzhong Qin and Xiaojun Jia and Jiangrui Gao},
journal= {arXiv preprint arXiv:1710.06706},
year = {2017}
}